still too slow

day10/sol2.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"bufio"
-	"container/heap"
 	"fmt"
 	"log"
 	"os"
@@ -114,40 +113,38 @@ func (h *CostHeap) Pop() any {
 	return x
 }
 
+// it doesn't matter what order we push the buttons in --
+// only how many times we push each one.
+
 func best(target Jolts, pool []Jolts) int {
 	var cost = make(map[Jolts]int)
-	h := &CostHeap{nil, cost}
-	heap.Push(h, Jolts{})
-	for h.Len() > 0 {
-		s := heap.Pop(h).(Jolts)
-		if s == target {
-			break
-		}
+	var states []Jolts
+	states = append(states, Jolts{})
+	cost[Jolts{}] = 0
+	for pi, p := range pool {
 		// enumerate all the states that can be reached by toggling button p
-	next:
-		for _, p := range pool {
-			t := s
+		queue := states
+		fmt.Print(pi, len(states), len(queue))
+		for _, s := range queue {
+		here:
+			for t, c := s, cost[s]; ; {
 				for i, v := range p {
 					t[i] += v
 					if t[i] > target[i] {
 						// blown target, cut path
-					continue next
+						break here
 					}
 				}
+				c += 1
 
 				if cost_t, ok := cost[t]; ok {
-				if cost[s]+1 < cost_t {
-					cost[t] = cost[s] + 1
-					for i, x := range h.heap {
-						if x == t {
-							heap.Fix(h, i)
-							break
-						}
-					}
+					if c < cost_t {
+						cost[t] = c
 					}
 				} else {
-				cost[t] = cost[s] + 1
-				heap.Push(h, t)
+					cost[t] = c
+					states = append(states, t)
+				}
 			}
 		}
 	}